FIELD OF THE INVENTION
The present invention relates to a device for mounting a dispensing valve on a container containing a product that is to be dispensed, with the aid of a pressurized gas, and to a dispenser equipped with such a device. More specifically, the present invention is aimed at improving dispensers commonly known as "aerosol dispensers".
Dispensers of the "aerosol" type are currently used for packaging and dispensing products in various fields, such as the field of cosmetics, dermopharmaceuticals, household or food, in the field of paint, health and hygiene, in the field of technical products, adhesives, insecticides, plant-treatment products, etc. In general, these products are dispensed in the form of a jet of liquid, gel, spray or foam/mousse.
Conventionally, an "aerosol" dispenser of this kind is made up of a container containing the product that is to be dispensed, of a dispensing valve collaborating with the dispensing head, such as a push-button equipped with an outlet orifice. A mounting device is provided for mounting the dispensing valve in a leaktight manner on the container. Actuation of the dispensing head makes it possible to set up a communication between the inside of the container and the dispensing orifice through actuation of the valve. Under the effect of a pressure inside the container, as a result, for example, of the action of a propellant gas, packaged in the container, actuation of the dispensing valve by the user causes a dose of product to be ejected.
Customarily, particularly in the case of "aerosol" dispensers, the dispensing valve is mounted on the container by means of a valve holder cup, generally made of metal. A cup such as this is obtained in a conventional way by stamping then drawing a roundel, made, for example, of tin plate.
A valve holder cup such as this must, in general, fill two functions: on the one hand, it must hold the dispensing valve in a leaktight manner inside the cup while allowing an actuation and dispensing means, such as an emerging valve stem, to pass to the outside, and on the other hand, it must be capable of being mounted in a leaktight manner on the open edge of the product container. In certain cases, the valve holder cup must also hold together various constituent parts of the valve which are located inside the valve body.
In the known way, the valve holder cup is mounted on the container and the valve is mounted in the cup by crimping or expansion rolling a portion of the cup onto the valve body and onto the open edge of the container, respectively.
The robustness of the mounting of the valve of the container is of prime importance because the internal pressure there may be inside an aerosol dispenser may be as high as 12 bar or even 15 bar. Metal valve holder cups mounted by crimping or expansion rolling are suitable for withstanding these pressures. However, there is a risk that this type of valve holder cup may be damaged by the product that is to be dispensed, particularly when this product contains corrosive components, unless that surface of the cup which comes in contact with the product is coated with a lacquer or some other inert thermoplastic layer.
However, mounting a valve holder cup provided with such a protective layer has the drawback that, during the crimping or expansion rolling of the cup, the protective lacquer or the anti-corrosion layer may become damaged.
Document FR-A-2 508 136 discloses an aerosol dispenser, in which the dispensing valve is mounted using a plastic device. However, this mounting device is designed to hold together the various components of the valve itself and at the same time mount this device on a product container. Furthermore, this mounting device is made up of various components which are complicated to mould and the assembly of which involves a number of stages. What is more, this device is ill-suited to the mounting of a conventional valve, available on the market at an economically viable price. Furthermore, the mounting device itself, according to FR-A-2 508 136, is relatively expensive. Finally, this device is unable to compensate for the manufacturing tolerances there are between the valve body and the open end of the product container.
Document DE-B-11 50 399 describes a plastic mounting device of the aforementioned kind. This device comprises a ring which, once a valve holder cup has been mounted on the product container, provides the cup with shape stability. The cup has a "U"-like structure in which the ring is inserted. The "U" is formed by a bottom and two lateral walls, of identical thickness. The thickness of these walls is relatively important. The cup is clipped on the container by means of an annular bulge situated on an external lateral wall of the "U". The mounting of the ring in the groove causes a radial extension of the external sidewalls of the groove. This mounting system has the drawback that it requires close dimensional tolerances on the cup, on the valve body and on the opening of the container, and the risk of leakage cannot be excluded. Furthermore, like in the prior-art device described hereinabove, this mounting system is ill-suited to the attaching of a conventional valve available commercially.